The Federal Railroad Administration Regulations (49 CFR Ch. II, xc2xa7 232.12) requires railroad train inspections which include the testing of a train""s air brakes via a procedure known as the Initial Terminal Inspection. Railway car brakes and locomotive brakes have air-brake systems. Each of these air-brake systems includes an auxiliary pressurized air reservoir and a brake pipe. The brake pipes of a plurality of cars and the locomotive are interconnected by means of flexible coupling hoses to provide a continuous air passage, known as the train air brake pipe or simply train brake pipe, extending from the locomotive to the last car of a made-up train. The train brake pipe is closed at the rear end of the train. A brake valve, usually located in the locomotive, controls the charge of compressed air from a main reservoir to the train brake pipe. The normal brake operating pressure retains the brakes of all the cars and the locomotive in a released or inoperative position. When the pressure in the train brake pipe is reduced from the normal operating pressure, all of the brakes of the train are applied and remain in the applied or operative position until the normal brake operating pressure is restored.
The brakes of each railway car must be tested and inspected when a train is assembled at a terminal to determine whether or not the brakes are properly applied and properly released under respectively reduced and normal operating pressures. This can advantageously be accomplished using a time-testing or clock release test device. In bief, with the cars of a train and the train brake pipe assembled (but normally without addition of a locomotive), the train brake pipe is charged to the desired pressure through the test device and then, with the train brake pipe closed to both the air supply and the air exhaust, the inspector watches a pressure gauge to determine brake pipe leakage. If the system is within permissible leakage tolerances, and with the pressure set to the brake application level, the inspector walks down the length of the train, examining the brakes of each car to assure that all brakes are in proper working order and that all brakes are in the set or applied position. Then the clock release test device, which has been preset to the estimated time required to walk the length of the train while examining each of the brakes, effectuates the restoration of normal operating pressures, triggering the release of the brakes. The inspector then returns, walking back up the length of the train, now examining the brakes of each car to assure that all are in the proper released position.
An unrefined embodiment of the time testing or clock release test device described in brief above is the subject of, and is described further in, U.S. Pat. No. 2,510,538, issued Jun. 6, 1950, inventor E. E. Andrews, the disclosures of which are incorporated hereinto. A much-refined commercial embodiment of such a clock release device, sold under the trademark TIME-O-TEST(copyright) by Railway Research, Inc. of Wheaton, Ill., has been, and well remains, on the market. There are hundreds or thousands of TIME-O-TEST(copyright) test devices in active daily use in commercial railroad yards. The TIME-O-TEST(copyright) device permits an inspector to examine each of the brakes in both the applied and the released positions with a single walk down the length of the train and a single return back up the length of the train. When test devices without a timed control mechanism for switching the pressure are used, the inspector must return to test device in between the applied and the released brake examinations, which requires walking the length of the train four times. The TIME-O-TEST(copyright) test device is connected to the brake pipe of a made-up train at the open, xe2x80x9clocomotive endxe2x80x9d of the brake pipe. (As noted above, the brake pipe is closed at the rear of the train.) It typically uses the yard""s compressed air supply, rather than compressed air from a locomotive, and thereby the brake test on the cars can be, and normally is, conducted without bringing over an expensive locomotive or crew therefor.
Although the TIME-O-TEST(copyright) clock release device functions very satisfactorily in most circumstances, there are situations in which the length of time required to walk the length of the train while conducting the first series of brake inspections is either not known or inadvertently does not sufficiently match the preset time for pressure restoration. If the brake release is triggered too early, that is before the completion of brake inspection in the set position, the inspector must return and reset the test device. If the brake release is set to be triggered only after too long of an elapse of time, an inspector might well be required to wait a significant length of time at the far end of the train for the brake release to be triggered.
It would be advantageous to efficiently and safely interface a remote control means to activate the triggering of the brake release, permitting an inspector to control the air brake test valve from various locations along the length of a train, particularly from the far end of a train after the inspector has completed a first series of brake examinations and is ready to start the second series.
The invention is an air brake testing apparatus comprising a supply of compressed air, an air line for establishing fluid communication between the compressed air supply and a train brake pipe of a line of coupled train cars whose air brakes are to be tested, a first valve assembly movable between a first position opening the air line for releasing the brakes and a second position closing the air line for applying the brakes, and a second valve assembly movable upon receipt of an input signal from a remote signal transmitter to an activated position actuating the movement of the first valve assembly from the second position to the first position. The present invention also includes a method of inspecting the air brakes of a made-up train employing an air brake testing apparatus of the invention.